Press angle control device, press machine facility, and press angle control method

Abstract

A device for reducing the press angle control error caused by press load variation, where the device includes: a reference value output unit that outputs a press angle reference value, a press angle detection unit, a speed command unit, and a driving unit. The press angle detection unit detects a press angle of the corresponding press machine and outputs a press angle detection value. The speed command unit outputs a command speed value of a motor of the corresponding press machine based on the press angle reference value and the press angle detection value. The driving unit controls the motor speed of the corresponding press machine based on the command speed value. The device further includes a correction unit that corrects the press angle reference value or the command speed value so the difference between the press angle reference value and the press angle is within a predetermined range.

What is claimed is: 
     
       1. A press angle control device for a press machine facility provided with a plurality of press machines constituting a press line, the press angle control device comprising:
 (a) a reference value output unit which outputs a press angle reference value; 
 (b) a plurality of press angle detection units; 
 (c) a plurality of speed command units; 
 (d) a plurality of driving units, wherein one press angle detection unit, one speed command unit and one driving unit are provided for each of the press machines, 
 wherein the press angle detection unit detects a press angle of the corresponding press machine and outputs a press angle detection value, 
 wherein the speed command unit outputs a command speed value to a motor of the corresponding press machine on the basis of the press angle reference value and the press angle detection value, 
 wherein the driving unit controls a speed of the motor of the corresponding press machine on the basis of the command speed value; and 
 (e) a correction unit that corrects the command speed value or the press angle reference value so that a difference between the press angle reference value and the press angle for each of the press machines is within a predetermined range, and wherein the correction unit corrects the command speed value or the press angle reference value so that the command speed value increases until a time point when a pressing process starts. 
 
     
     
       2. The press angle control device according to  claim 1 , wherein the correction unit corrects the command speed value or the press angle reference value so that a press angle difference between the adjacent press machines is within a predetermined range. 
     
     
       3. The press angle control device according to  claim 1 , wherein the correction unit corrects the command speed value or the press angle reference value so that the command speed value decreases after the pressing process starts. 
     
     
       4. A press machine facility comprising:
 (a) a plurality of press machines, wherein the plurality of press machines constitute a press line, wherein each press machine has a press angle; and 
 (b) a press angle control device that controls the press angles of the plurality of press machines, 
 wherein the press angle control device includes
 (i) a reference value output unit that outputs a press angle reference value; 
 (ii) a plurality of press angle detection units; 
 (iii) a plurality of speed command units; and 
 (iv) a plurality of driving units, wherein one press angle detection unit, one speed command unit, and one driving unit are provided for each of the press machines, 
 
 wherein the press angle detection unit detects the press angle of the corresponding press machine and outputs a press angle detection value, 
 wherein the speed command unit outputs a command speed value to a motor of the corresponding press machine on the basis of the press angle reference value and the press angle detection value, 
 wherein the driving unit controls a speed of the motor of the corresponding press machine on the basis of the command speed value; and 
 (e) a correction unit that corrects the command speed value or the press angle reference value so that a difference between the press angle reference value and the press angle for each of the press machines is within a predetermined range, and wherein the correction unit corrects the command speed value or the press angle reference value so that the command speed value increases until a time point when a pressing process starts. 
 
     
     
       5. A press angle control method for a press machine facility provided with a plurality of press machines constituting a press line, the method comprising the steps of:
 (a) outputting a press angle reference value from a reference value output unit, 
 (b) detecting a press angle of a corresponding press machine, 
 (c) outputting a press angle detection value, wherein a press angle detection unit detects the press angle of the corresponding press machine and outputs the press angle detection value, 
 (d) outputting a command speed value to a motor of the press machine on the basis of the press angle reference value and the press angle detection value, wherein the command speed value is outputted by a speed command unit, 
 (e) controlling a speed of the motor of the press machine on the basis of the command speed value, wherein the speed of the motor of the press machine is controlled by a driving unit; and 
 (f) correcting the command speed value or the press angle reference value so that a difference between the press angle reference value and the press angle for each of the press machines is within a predetermined range, wherein the command speed value and the press angle reference value are corrected by a correction unit, and wherein the correction unit corrects the command speed value or the press angle reference value so that the command speed value increases until a time point when a pressing process starts. 
 
     
     
       6. The press angle control method according to  claim 5 , wherein the correction unit corrects the command speed value or the press angle reference value so that a press angle difference between the adjacent press machines is within a predetermined range. 
     
     
       7. The press angle control device according to  claim 2 , wherein the correction unit corrects the command speed value or the press angle reference value so that the command speed value decreases after the pressing process starts.